LTC4244

Features:

`Controls 12V, 3.3V, 5V and 12V Supplies
`±14.4V Absolute Maximum Rating for 12VIN and 12VIN Input Pins
`Insensitive to Supply Voltage Transients
`Adjustable Foldback Current Limit with Circuit Breaker
`LOCAL_PCI_RST# Logic On-Chip
`PRECHARGE Output Biases I/O Pins During Card Insertion and Extraction
`LTC4244-1 Designed for Applications without 12V
`Available in 20-Lead Narrow SSOP Package


Application

Hot Board Insertion into CompactPCI Bus


Specifications

Supply Voltages
12VIN ........................................................................... 14.4V
VEEIN ........................................................................ 14.4V
Input Voltages (OFF/ON, RESETIN ) ................0.3V to 13.5V
Output Voltages (FAULT, PWRGD , RESETOUT )
.......................................................................0.3V to 13.5V
Analog Voltages and Currents
5V_OUT, DRIVE, 5V_IN, 3.3V_SENSE, 3.3V_IN, 3.3V_OUT, 5V_SENSE
........................................................................0.3V to 13.5V
PRECHARGE, GATE ...................................................... ±20mA
VEEOUT .......................................................... 14.4V to 0.3V
TIMER, 12VOUT ................................................0.3V to 14.4V
Operation Temperature Range
LTC4244C/LTC4244C-1........................................... 0 to 70
LTC4244I/LTC4244I-1 ....................................... 40 to 85
Storage Temperature Range ........................... 65 to 150
Lead Temperature (Soldering, 10 sec)............................. 300 


Description

The LTC®4244/LTC4244-1 are Hot SwapTM controllers that allow a board to be safely inserted into and removed from a CompactPCITM bus slot. External N-channel transistors control the 5V and 3.3V supplies while on-chip switches control the ±12V supplies. The 3.3V and 5V supplies of LTC4244 can be ramped up at an adjustable rate. Electronic circuit breakers protect all four supplies against overcurrent faults. After the power-up cycle is complete, the TIMER pin capacitor serves as auxiliary VCC allowing the LTC4244/LTC4244-1 to function without interruption in the presence of voltage spikes on the 12VIN supply. The PWRGD output indicates when all four supplies are within tolerance.

The OFF/ON pin of LTC4244 is used to cycle board power or reset the circuit breaker. The PRECHARGE output can be used to bias the bus I/O pins during card insertion and extraction.

PCI_RST# of LTC4244 is combined on-chip with HEALTHY# in order to generate LOCAL_PCI_RST#.